210001012121 has 4 divisors (see below), whose sum is σ = 222354012852. Its totient is φ = 197648011392.

The previous prime is 210001012103. The next prime is 210001012129. The reversal of 210001012121 is 121210100012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 109435917721 + 100565094400 = 330811^2 + 317120^2 .

It is a cyclic number.

It is not a de Polignac number, because 210001012121 - 2¹⁰ = 210001011097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (210001012129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6176500340 + ... + 6176500373.

It is an arithmetic number, because the mean of its divisors is an integer number (55588503213).

Almost surely, 2^210001012121 is an apocalyptic number.

It is an amenable number.

210001012121 is a deficient number, since it is larger than the sum of its proper divisors (12353000731).

210001012121 is a wasteful number, since it uses less digits than its factorization.

210001012121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12353000730.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 210001012121 its reverse (121210100012), we get a palindrome (331211112133).

The spelling of 210001012121 in words is "two hundred ten billion, one million, twelve thousand, one hundred twenty-one".